These easy lime bars have a puckery lime filling that sits on top of a buttery shortbread crust! Fresh limes are used to create the best lime flavor, along with some powdered sugar sprinkled over the top for a touch of sweetness.
Preheat the oven to 350 degrees. Line an 8×8-inch baking pan with foil, allowing a little to come up the sides. Then spray the sides of the pan and the foil with non-stick spray.
Shortbread Crust
In a medium-sized bowl, whisk together the flour, melted butter, powdered sugar, vanilla extract, and salt with a wooden or plastic spoon. Press the dough into the prepared pan with your fingers and bake for 16-20 minutes or until the edges start to turn light brown.
Lime Filling
In a large bowl, whisk together the sugar, flour, baking powder, and salt. Then add the lime juice, lime zest, and the eggs and whisk until combined.
When the crust is done, reduce the oven temperature to 325 degrees. Pour the lime filling over the hot crust and bake for 15-18 minutes or until the middle is set and does not jiggle when you move the pan. Let the bars cool at room temperature for 1 hour, then place them into the refrigerator to cool for another 2 hours.
Once the bars are completely set and cooled, use the extra foil that is along the sides of the pan to pull the bars out. Dust the bars with powdered sugar and cut into bars. Use a butter knife or a serrated knife to cleanly cut the bars. Wipe the knife clean after each cut.
Keep any leftover lime bars in an airtight container in the refrigerator for up to 5 days.
Notes:
Baking Pan: Line an 8x8-inch baking pan with aluminum foil, allowing a little to come up the sides. Then generously spray the foil and the sides of the pan with non-stick spray. You could also use parchment paper.
Lemon Squeezer: I highly recommend this lemon squeezer. It's a lifesaver for me when I bake anything with lemons or limes! Plus, you can use it for other citrus fruit as well.
Green Food Coloring: Adding just a drop or two of green food gel will give the bars a green color that matches the limes. Without it, the lime curd has more of a yellow color, which is perfectly fine!
Oven Temperature: The crust will be baked at 350 degrees. Then lower the temperature to 325 degrees when the lime layer is added to the crust. This helps the lime filling to not overcook.
Cooling: Before slicing and serving, the bars need to be completely cooled and set. Cool at room temperature for 1 hour, and then an additional 2 hours in the refrigerator.